package com.example.demo.config;

import com.example.demo.common.ResultAjax;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

/**
 * 对返回的数据类型做强制的数据转换
 */

@ControllerAdvice
public class ResponseAdvice implements ResponseBodyAdvice {

    @Autowired
    private ObjectMapper objectMapper;



    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return true;
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
           if (body instanceof ResultAjax) {
               return body;
           }
           if (body instanceof String) {
               try {
                  ResultAjax resultAjax = ResultAjax.success(objectMapper.writeValueAsString(body));
                  return objectMapper.writeValueAsString(resultAjax);
               } catch (JsonProcessingException e) {
                   e.printStackTrace();
               }
           }
           return ResultAjax.success(body);
    }
}
